As more and more businesses are conducted via the Internet, customer experience on the Web has become critically important. In both business to consumer (B2C) and business to business (B2B) spaces, customer loyalty can easily be damaged if a Web site fails to provide satisfactory services in the form of fast response times. This is especially true during the period when the system is under overloaded conditions. With the global nature of the Web and the difficulty in predicting user demands, overloaded conditions are likely to occur quite frequently on the Internet. Hence, it is important to examine the way Web services are provided on the Internet under overloaded conditions.
Current practices in providing services on the Web under overloaded conditions are highly undesirable. Generally, users are either kept waiting for the system to return something or they are provided with a simple message indicating “server not found”. In either case, not much useful information has been conveyed to the users, leaving them totally in the dark. Not knowing what happened, many of them might repeatedly hit the reload” button on their browsers. As a result, even more traffic will be generated, compounding an already overloaded condition. Under such circumstances, many users can be frustrated. Customer loyalty and business reputation can be severely damaged. Hence, a need is recognized for providing more satisfactory services on the Internet even in the face of overloaded conditions.
In the present invention, a system and method are disclosed to provide gracefully degraded services on the Internet under overloaded conditions. The phrase “gracefully responsive” is meant to indicate or signify the opposite of responding in a manner that is inhospitable or lacking in grace such as by total silence or, curtly, by “server not found”, which are customary types of responses. Instead of keeping the users waiting or giving simple “server not found” messages, various kinds of gracefully degraded services can be immediately provided. For example, users of an overloaded Web site can receive a page with much more information in it. The system can provide a more responsive page that contains the following message: “Our servers are experiencing extremely high demands now, please come back in 5 minutes.” This way the demands can be spread over a longer period of time, reducing the immediate system load. When the customers indeed return as suggested in a later time, the system will service them as promised. Understanding what is happening, most customers will be more willing to wait and come back at a later time. In the case of video or image pages, lower resolution contents can be delivered instead of the original high resolution ones. Hence, bandwidth usage can be reduced and more users can be served. In other words, lesser quality of services can still be provided even in the face of an overloaded condition.
In light of today's emerging Internet service infrastructure, the gracefully degraded services disclosed in the present invention can be implemented in one or more places on the Internet. Many of the content provider Web sites, both B2C and B2B, are usually hosted in a data center by a content hoster, such as IBM Global Services or Exodus Communications, Inc. The data centers of a content hoster are generally located on the core of the Internet. Web users, especially consumers and small businesses, are generally connected to the Internet via an Internet Service Provider (ISP), such as AOL or Earthlink Inc. The points of access of an ISP are generally located on the edge of the Internet. For both content hosters and ISPs, extra resources are typically reserved for handling future demand growth. Part of these extra resources can be used to provide gracefully degraded services. The gracefully degraded services disclosed in the present invention can be implemented by the content hosters or the ISPs.
There are advantages to various participants in providing gracefully degraded services on the Internet. For Web users, they will be less likely to become unhappy because they can receive more responsive services. For content providers, they can maintain their brand loyalty by offering gracefully degraded services to their customers. They can better handle unexpected demand spikes. Moreover, they can better deal with the demand mismatch caused by poor capacity planning. Inaccurate capacity planning happens, especially when a new service is first offered or a promotional campaign is started. Finally, for content hosters, they may charge content providers with premium prices for gracefully handling demand spikes or poor capacity planning. Content hosters can also maintain a certain service quality during the period when extra resources are dynamically added.
In the above-referenced commonly assigned US Patent Application by Chaar and Chang, U.S. Pat. No. 6,859,020, entitled “Apparatus, System, and Method for Managing Quality-of-Service-Assured e-Business Service Systems,” a general Service Level Agreement (SLA) monitoring system was disclosed. An SLA is a legal document describing the service contract between a content provider and the content hoster. Their goal is to monitor and enforce SLAs. Certain actions, such as increasing resources, can be taken to fulfill the obligations bound by the SLAs. No specific system or method in Chaar and Change were disclosed to provide gracefully degraded services in the face of overloaded conditions, even though gracefully degraded services disclosed in the present invention can be signed into legal contracts between the content hoster and the content providers.
In the above-referenced commonly assigned US Patent Application by Maruyama et al, U.S. Pat. No. 6,859,025, entitled “Highly Scalable System and Method of Regulating Internet Traffic to Server Farm to Support (min,max) Bandwidth Usage-based Service Level Agreements,” a method was disclosed to control the incoming traffic to a server farm so that the output of the server farm can meet the requirements of SLAs. Requests may be dropped in order to meet the SLA requirements. Although regulating incoming traffic can reduce potential overloaded conditions, no specific mechanism was disclosed by Maruyama et al to provide gracefully degraded services as disclosed in the present invention.
In the above-referenced commonly assigned US Patent Application by Mei et al, U.S. Pat. No. 6,816,907, entitled “System and Method for Providing Differentiated Services on the Web,” a method to provide differentiated services on the Web in the form of faster response times to preferred customers of a Web site was disclosed. Priority tables were used to allocate resources to a subset of preferred customers so that their requests could be serviced with higher priorities. No specific system or method in Mei et al were disclosed to provide gracefully degraded services under overloaded conditions, even though the response page for degraded services disclosed in the present invention is handled immediately with a higher priority.
Thus, there is a need to have a system and method for providing gracefully degraded services on the Internet under overloaded conditions.
Accordingly, it is a primary object of this present invention to enable such degraded services to be available to the user when overloaded conditions arise.